-LRB- CNN -RRB- -- The flight data and cockpit voice recorders from JetBlue Flight 191 , which made an emergency landing this week , have been retrieved and will be analyzed , officials said Thursday .

The National Transportation Safety Board will download the data Friday , said spokeswoman Kelly Nantel . Information gleaned from them will be given to the FBI , she said .

Investigators are looking into the apparent midair meltdown of the captain , Clayton Osbon , whose remarks and erratic behavior Tuesday led the co-pilot to lock him out of the cockpit .

Crew and passengers subdued Osbon as he screamed and banged on the door so hard the first officer thought Osbon would come through , according to a federal criminal complaint filed Wednesday against Osbon .

The complaint says Osbon began making remarks during the flight that concerned the first officer , who is his co-pilot .

`` Osbon yelled over the radio to air traffic control and instructed them to be quiet . Osbon turned off the radios in the aircraft , dimmed his monitors and sternly admonished the FO -LRB- first officer -RRB- for trying to talk on the radio , '' the U.S. attorney 's office in the Northern District of Texas said in a written statement . `` When Osbon said ` we need to take a leap of faith , ' the FO stated that he became very worried . Osbon told the FO that ` we 're not going to Vegas , ' and began giving what the FO described as a sermon . ''

It was not immediately known whether the alleged remarks are audible on the voice recorder . But federal regulations state that planes manufactured since 1991 must record cockpit chatter on microphones . The JetBlue plane was new and would be subject to the rule .

The cockpit voice recorder captures two hours of data and the flight data recorder , which measures the plane 's speed and altitude , contains 25 hours .

About 3Â 1/2 hours into the planned five-hour flight from New York 's Kennedy International Airport to Las Vegas , the pilot left the cockpit to use the lavatory , but he failed to follow security protocol , alarming the crew , according to an affidavit filed in support of an arrest warrant . He then banged on the lavatory door and told the female passenger inside that he needed to go to the bathroom .

By that time , the first officer had summoned another JetBlue pilot who had been traveling as a passenger to enter the cockpit and the two locked themselves inside , the affidavit states .

From the cabin , Osbon tried to enter his security code to gain access to the cockpit `` and he banged on the door hard enough that the FO thought he was coming through the door , '' according to the affidavit . But the door held and , over the PA , the first officer ordered passengers to restrain Osbon . Several did just that , subduing the pilot in the forward galley .

Osbon , who was been charged with interfering with a flight crew , has not made a public statement . He has been suspended pending an investigation and is receiving medical treatment , the airline said Wednesday . A court official said Osbon was still under care Thursday .

JetBlue has repeatedly praised the first officer , along with an off-duty captain who stepped in to assist and other crew members .

Some passengers have referred to the first officer as a hero . But his mother said on Thursday that he would reject the label .

`` Knowing my son , he would think that he 's not a hero . He just did what he was paid to do , '' Jean Beatrice Dowd said of Jason Dowd .

`` That 's just his job , and he loves his job . He 's just a quiet man . ''

He called his parents the night of the incident , his mother said . `` He was pretty shaken up , and he could n't say much . ''

The incident took place on a significant date for the family -- the 10th anniversary of the death of Jason Dowd 's older sister , who died of cancer , Jean Dowd said .

`` I know he was thinking of her , too , at the time this was all going on , '' Dowd said .

The incident `` has been earthshaking for us , too , '' she said . `` To lose him would have been terrible for us . ''

Jason Dowd , 41 , who is married and has two young children , has not made a public statement . He was in New York , speaking with officials about the incident , his mother said .

After the incident , the flight made the emergency landing in Amarillo , Texas .

Osbon 's stepmother said Thursday she has flown with him several times .

`` He loved to fly , a love which he got from his dad , '' Judy Osbon said in a statement . `` He also took his piloting very seriously and was very good at it . I 've only known Clayton to be a cheerful , conscientious and caring person . ''

Her stepson was upbeat the last time they spoke , she said .

Osbon 's father , Ronald , who was a pilot , and a passenger were killed in a 1995 airplane crash in Florida , according to the National Transportation Safety Board . The pilot radioed he was losing power on both engines and was out of gas . The aircraft crashed near Daytona Beach Regional Airport .

CNN 's Aaron Cooper , Mike M. Ahlers and Carol Cratty contributed to this report .

@highlight

Investigators are looking into the apparent midair meltdown of flight 's captain

@highlight

Data and voice recorders given to NTSB

@highlight

Federal regulations : Recorders must tape conversations on planes made since 1991

@highlight

The co-pilot 's mother says he would not consider himself a hero